DuReg is a command-line tool that enables you to discover how much data is stored in the registry, or in any registry subtree, key, or subkey. The tool also enables you to search for all occurrences of a text string in the registry. This search can be limited to a specific subtree. The DuReg helps developers and administrators estimate how much space registry data is consuming. Developers can use this tool to discover how much data they are contributing to the registry. Administrators can use this tool to investigate which applications are filling a registry when the registry approaches its maximum size. The registry data size function is unique to each system. You can determine the maximum registry size and an estimate of the current registry size by using System in Control Panel. You can also find the current:maximum size ratio (expressed as a percentage) by using the System: % Registry Quota in Use counter in PerfmonSysmon. However, only DuReg returns the size of individual keys and subkeys. With Dureg ou can easily view the amount of data stored in various areas of the system registry.